. >> reporter: san francisco school districtsuperintendentrichardcarranzasayshe wants to remind parents that the schools have safety plans and that teachers drill on how to keep the kids out of danger. but school officials emphasize there is no security measure as good as paying attention to a person who seems to be plotting an evil deed and calling the police right away. >> as a teacher during the columbine incident there was a rush to install security metal detectors and all of this hardware. i will tell you the single greatest security system you can have in place is a well informed enabled student body. >> reporter: you saw those parents hugging their kids a little tighter. well, one school district official told me that, you know, after you have the conversation with your children tonight, maybe it's time for a little extra dessert as well, allen, as people just want to show that little extra display of love today in a moment like this. >> a lot of us will be displaying extra love tonight. thank you, joe vazquez. >>> president obama reacted to the massacre not only as our presiden